A late merge is named however its modules read since the cut; a walk builds the commits it carries (hq ADR 0276 review)

cmd/mesh-controller/batches_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"io"
 	"os"
 	"slices"
@@ -137,8 +138,8 @@ func TestTwoMergesSecondsApartAreOneWalkAtTheLaterCommit(t *testing.T) {
 	if w.Delivery == nil || !slices.Equal(w.Delivery.Merges, want) {
 		t.Fatalf("the walk answers %+v, want %+v", w.Delivery, want)
 	}
-	if len(*asked) != 2 {
-		t.Fatalf("the walk asked %v", *asked)
+	if len(*asked) != 2 || (*asked)[0][2] != dunst.Commit || (*asked)[1][2] != dunst.Commit {
+		t.Fatalf("the walk did not ask its modules at the commit it carries: %v", *asked)
 	}
 	// Heard again, as the bus may hand it over twice: never a second merge, nor a second walk.
 	hear(t, open, claude, t0.Add(5*time.Minute))
@@ -378,7 +379,7 @@ func TestALateMergeIsAnsweredByTheWalkOfTheLaterOne(t *testing.T) {
 // first; the first delivered answers the older ones, and the search stops.
 func TestAFailedWalkWalksItsEarlierMergesAlone(t *testing.T) {
 	open := windowed(t)
-	asksWithPaths(t)
+	asked := asksWithPaths(t)
 	ctx := t.Context()
 	oldest := catalogueMerge("aaaa0001", "app", t0)
 	middle := catalogueMerge("bbbb0002", "app", t0.Add(10*time.Second))
@@ -404,6 +405,14 @@ func TestAFailedWalkWalksItsEarlierMergesAlone(t *testing.T) {
 		alone.Delivery.Merges[0] != (inventory.PlanMerge{Repository: "novox/mesh-catalog", Commit: middle.Commit}) {
 		t.Fatalf("the newest earlier merge was not walked alone on its own commit: %+v", alone)
 	}
+	if _, in := alone.Modules["app"]; !in || (*asked)[len(*asked)-1] != [3]string{"novox/mesh-catalog", "modules/app",
+		middle.Commit} {
+		t.Fatalf("the merge walked alone does not build app at its own commit: %v, asked %v", alone.Modules, *asked)
+	}
+	// Retried, the failed walk would name merges the search answers now.
+	if _, err := retryPlan(ctx, open, failed.ID); err == nil || !strings.Contains(err.Error(), "walked alone") {
+		t.Fatalf("a failed walk whose merges are searched was retried: %v", err)
+	}
 	alone.State = inventory.PlanDone
 	if err := open.inventory.SavePlan(ctx, &alone); err != nil {
 		t.Fatal(err)
@@ -535,3 +544,83 @@ func TestAWaitingWalkNamesTheMergesItAnswers(t *testing.T) {
 		t.Fatalf("the waiting walk does not name both merges: %+v", got)
 	}
 }
+
+// A merge heard after a later merge of its branch was cut is named by that walk however its modules read since
+// the cut, in a repository of one module (review of this change); a walk that never built what it moves names
+// nothing, and the merge joins the next batch.
+func TestALateMergeOfAOneModuleRepositoryIsNamed(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	c2 := repoMerge("one", "c2", t0.Add(-50*time.Second))
+	hear(t, open, c2, t0)
+	cutAt(t, open, t0.Add(2*time.Minute))
+	ws, _ := walks(t, open)
+	w := ws[0]
+	w.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &w); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, repoMerge("one", "c1", t0.Add(-60*time.Second)), t0.Add(15*time.Minute))
+	got, _ := open.inventory.PlanByID(ctx, w.ID)
+	if len(got.Delivery.Merges) != 2 || got.Delivery.Merges[0] != (inventory.PlanMerge{Repository: "novox/one",
+		Commit: "c1", Carried: "c2"}) {
+		t.Fatalf("the late merge was not named by the walk that carried it: %+v", got.Delivery.Merges)
+	}
+
+	// A walk of two that built only two: a late merge of one is not its to name.
+	hear(t, open, repoMerge("two", "d2", t0.Add(16*time.Minute)), t0.Add(16*time.Minute))
+	cutAt(t, open, t0.Add(18*time.Minute))
+	ws, _ = walks(t, open)
+	w = ws[0]
+	delete(w.Modules, "two")
+	w.State = inventory.PlanDone
+	if err := open.inventory.SavePlan(ctx, &w); err != nil {
+		t.Fatal(err)
+	}
+	hear(t, open, repoMerge("two", "d1", t0.Add(15*time.Minute)), t0.Add(20*time.Minute))
+	if got, _ := open.inventory.PlanByID(ctx, w.ID); len(got.Delivery.Merges) != 1 {
+		t.Fatalf("a walk that never built what the late merge moves named it: %+v", got.Delivery.Merges)
+	}
+	if _, bs := walks(t, open); len(bs) != 1 || bs[0].Delivery.Merges[0].Commit != "d1" {
+		t.Fatalf("the late merge did not join the next batch: %+v", bs)
+	}
+}
+
+// One walk at a time holds against the delivery's word too: a waiting walk is not let go while another started.
+func TestAWaitingWalkIsNotLetGoBesideAStartedOne(t *testing.T) {
+	open := windowed(t)
+	asksWithPaths(t)
+	ctx := t.Context()
+	hear(t, open, repoMerge("one", "c1", t0), t0)
+	cutAt(t, open, t0.Add(2*time.Minute))
+	started, _ := walks(t, open)
+	waiting := inventory.Plan{ID: "plan-waiting", Repository: "novox/two", Branch: "main", Commit: "d1", Created: t0,
+		State: inventory.PlanBuilding, Tiers: [][]string{{"two"}}, Modules: map[string]*inventory.PlanModule{"two": {}},
+		Delivery: &inventory.PlanDelivery{Awaits: catalogue.DeliverySeat}}
+	if err := open.inventory.SavePlan(ctx, &waiting); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := letGo(ctx, open.inventory, waiting.ID, catalogue.DeliverySeat, "its turn"); err == nil ||
+		!strings.Contains(err.Error(), started[0].ID) {
+		t.Fatalf("a waiting walk was let go beside %s: %v", started[0].ID, err)
+	}
+}
+
+// A file a merge of the batch removed and a later one brought back is not removed; one removed last is.
+func TestARemovedFileIsTheLastMergesWord(t *testing.T) {
+	ev := func(commit string, paths, removed []string) inventory.BatchedMerge {
+		m := link.SourceMoved{Owner: "novox", Repo: "one", Base: "main", Commit: commit, Paths: paths, Removed: removed}
+		b, _ := json.Marshal(m)
+		return inventory.BatchedMerge{Repository: "novox/one", Branch: "main", Commit: commit, Event: b,
+			Merged: t0.Add(time.Duration(len(commit)) * time.Second)}
+	}
+	got := combinedMerges([]inventory.BatchedMerge{
+		ev("a", []string{"x/module.json", "y/module.json"}, []string{"x/module.json", "y/module.json"}),
+		ev("bb", []string{"x/module.json"}, nil),
+		ev("ccc", []string{"z.go"}, nil)})
+	if len(got) != 1 || got[0].Commit != "ccc" || !slices.Equal(got[0].Removed, []string{"y/module.json"}) ||
+		len(got[0].Paths) != 3 {
+		t.Fatalf("combined as %+v", got)
+	}
+}